Rotary compressor

ABSTRACT

A rotary compressor comprising a lubricant reservoir placed in the lower part of a compressor body; and a lubricant circulating mechanism for cooling lubricant received in said reservoir by conducting it through a tubing provided with a heat exchanger and supplying the lubricant thus cooled to the compressing unit of said body and those sections of said body through which there slides a blade.

D United States Patent 11 1 1111 3,746,477 Ozu et a1. July 17, 1973 [54]ROTARY COMPRESSOR 3,003,684 10/1961 Tarleton 417 410 3,111,820 11/1963Atchison 418/99 [75] Invemms: K Shmsak bmh of 3,513,476 5/1970 Monden417/902 l Japan 2,134,936 11/1938 Getchell et al. 417 902 2,669,3842/1954 Dills 418/88 [73] Asslgnee g z g g f gi 2,623,365 12/1952 Daniel418/85 22 7 1 Filed, Apr 19 1 Primary Examiner-William L. Freeh [21]Appl. No.: 137,851 Assistant Examiner.lohn Tr Winburn Attorney-Flynn &Frishauf [30] Foreign Application Priority Data May 1, 1970 Japan45/42339 May 30, 1970 Japan 45/52948 [57] ABSTRACT A rotary compressorcomprising a lubricant reservoir [52] 9.8.81. 3117437136411 3/9412placed in the lower part of a Compressor body; and a 2 'f d 4 902lubricant circulating mechanism for cooling lubricant I 1 j rz 3 5received in said reservoir by conducting it through a l I tubingprovided with a heat exchanger and supplying the lubricant thus cooledto the compressing unit of said body and those sections of said bodythrough [56] 1 uNlTE g s fr lz lis ll zqrENTs which there slides ablade. 2,225,228 12/1940 Neeson 184/628 8 Claims, 4 Drawing FiguresROTARY COMPRESSOR BACKGROUND OF THE INVENTION This invention relates toa rotary compressor pro vided with a lubricant circulating mechanism tocool lubricant. 7

With conventional compressors, lubricant is cooled by conducting part ofa gaseous refrigerant previously cooled in a condenser through a pipingdisposed in a lubricant reservoir. Since, however, a gaseous refrigeranthas a far smaller heat transfer coefficient and specific heat atconstant pressure than lubricant, this cooling method is extremelyinefficient. There are disadvantages that the unavoidable shaking of thepiping decreases the efficiency of a compressor and the additionalinstallation of the piping leads to the complicated construction of acompressor and increased manufacturing cost.

The prior art compressor of the aforementioned type does not permit anyejecting action following the principle of the Venturi meter to beutilized in circulating cooled lubricant through a heat exchanger,presenting the drawback that there must be provided bulky circulationmeans outside of the compressor.

SUMMARY OF THE INVENTION A rotary compressor according to this inventioncomprises a motor fitted with a main shaft; a refrigerant compressingunit actuated by an eccentric attached to the main shaft and providedwith a blade chamber; and a lubricant circulating mechanism including alubricant tubing passing through a heat exchanger, open at one end tothe lubricant in the reservoir and communicating at the other end withat least a compressing unit and those sections of a compressor bodythrough which there slidesa blade in the blade chamber, thereby coolinglubricant by. conducting it through said tubing according to therotation of the main shaft and supplying the lubricant thus cooled tosaid blade sliding sections.

According to a feature of this invention a rotary compressor is providedwith a lubricant circulating mechanism for conducting lubricant only inone direction through a tubing penetrating a heat exchanger for coolingthe lubricant in the tubing while an electric motor is driven to operatea refrigerant compressing unit.

According to a further feature of the invention a rotary compressor isprovided with a valve unit cooperating with a blade chamber so as tocool lubricant by circulating it through a tubing penetrating a heatexchanger.

A still further feature of the invention is to provide a rotarycompressor which is little subject to failure and which is formed of asmall number of easily assembled parts and adaptedfor miniaturizationand quantity production with reduced cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially exploded sideview of a rotary compressor according to an embodiment of thisinvention;

FIG. 2 is a sectional view along line 2--2 of FIG. 1;

FIG. 3 illustrates the operating condition of a valve unit where thereis sucked lubricant into a blade chamber; and

- FIG. 4 illustrates the operating condition of a valve unit where thereis discharged lubricant from the blade chamber into its reservoir.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, numeral 1represents a compressor body tightly closed by upper and lower casings 2and 3. In the upper casing 2, there is fixedly received an electricmotor 4 in such a manner that a main shaft 5 thereof projects downwardlytherefrom. In the lower casing 3 is disposed a refrigerant compressingunit 7 and a reservoir 8 filled with lubricant 9. The inner walls of thelower casing 3 define a lubricant reservoir 8 in which lubricant 9 iscontained. However, the lubricant reservoir may be separately providedin the lower cas ing.

Numeral l0 denotes a lubricant circulating mechanism actuated by therotation of the main shaft 5, the lower part of said mechanism beingimmersed in the lubricant 9. To the lower side wall of the lower casing3 is connected one end 1 la of a lubricant tubing ll so as tocommunicate with the reservoir 8. The other end 11b of the lubricanttubing 11 is connected to the lubricant circulating mechanism 10. Thegreater part of said lubricant tubing 11 passes through a radiator, forexample, a heat exchanger 12 provided with fins 13.

To that portion of the main shaft 5 which projects downward of theelectric motor 4 is eccentrically fixed an eccentric or an eccentricdisk member 14 which is fitted into a portion 15. Concentrically withthe main shaft 5 is disposed a cylinder 16, the cylindrically innersurface 16b of which contacts that portion 15b of the outer periphery15b of the rotor 15 which is remotest from the axis of the main shaft 5.The top andbottom surfaces of the cylinder 16 contact airtight with anupper frame 6 and a lower frame 17 which support the main shaft 5respectively. The rotor 15 slides airtight on the lower surface of theupper frame 6 and the upper surface of the lower frame 17.

Referring to FIGS. 1 and 2, the side wall of the cylinder 16 isperforated with a slit 18 for guiding a blade 19. The blade 19 is urgedby springs 20 so as always to have an the inner end surface thereofbrought into contact with the outer periphery of the rotor 15. Thus,said blade 19 reciprocates in the radial direction of the cylinder 16(in the directions of the arrows a and b of FIGS. 1 and 2) in a statealways pressed thereby as the rotor 15 rotates. A blade chamber 22 isprovided in the swollen portion of the wall 16c of the cylinder 16.Below the blade chamber 22 is provided a lubricant valve unit 23constructed substantially in integral relationship with the lower frame17. A valve chamber 24 of the valve unit 23 communicates with the bladechamber 22 through a lubricant passage 25. The end of the lubricanttubing 11b communicates with the chamber 24 through a suction port 26connected to the lower casing 3 and extending in the chamber 24. In thevalve chamber 24, there is so disposed a ball 27 as to be urged by aspring 28, thereby normally closing the suction port 26. To the lowerend of the valve unit 23 is fitted a plate 29 made of elastic materialnormally to close a discharge port 30. When the port 30 is opened, thevalve cavity 24 to communicate with the lubricant reservoir 8. Thelubricant circulating mechanism 10 comprises the blade chamber 22 andvalve unit 23.

As shown in FIG. 2, the refrigerant compressing unit 7 is formed of therotor 15 rotatably engaging the eccentric 14, the cylinder 16 whoseinner wall always contacts the remotest portion 15b of the outerperiphery 15a of the rotor 15 and the blade 19 always pressed againstthe periphery of the rotor 15 so as to divide the space between therotor 15 and cylinder 16 into a high pressure side 70 and low pressureside 71;. Said refrigerant compressing unit 7 is constructed in the samemanner as an ordinary rotary pump, compressing gaseous refrigerantsucked in from a suction line 31 for refrigerant and delivering it fromits discharge line 32 through the space 33 of the upper casing 2. Itwill be noted at this point that a refrigerant tubing comprises thesuction and discharge lines 31 and 32. It is assumed for convenience ofdescription that the main shaft 5 rotates clockwise as viewed from FIG.2.

In FIG. 2 numeral 34 denotes a discharge port open to a high pressureside 7a and a discharge chamber 35 defined by the upper and lower frames6 and 17 and the swollen portion 16a of the wall 160 of the cylinder 16.To that opening of the discharge port 34 which faces the dischargechamber 35 there is fitted a check valve 36 for conducting gaseousrefrigerant from the high pressure 7a only to the discharge chamber 35.In the upper frame 6 is disposed a passage 39 (FIG. 1) for allowing thedischarge chamber 35 to communicate with a space 33 defined by the innerwalls of the upper casing 2. The high pressure side 7a may directlycommunicate with said space 33 without providing the discharge chamber35. In that part of the swollen portion 16a of the cylinder 16 which isopposite to the discharge chambers 35 with respect to the blade chamber22 is provided a suction chamber 21 communicating with the low pressureside 7b. The suction line 31 is connected to said suction chamber 21.

In the peripheral surface of the main shaft 5 is formed a spiral groove37 communicating with a lubricant passage 38 bored in the main shaft 5and open to the lubricant 9 at the lower end of the main shaft 5.

There will now be described by reference to FIGS. 1 and 2 the operationof a rotary compressor according to an embodiment of this invention.When the eccentric 14 rotates with the main shaft 5 by the electricmotor 4, the blade 19 is made to slide back and forth in the radialdirection of the cylinder 16 while abutting against the periphery of therotor 15. Now let it be assumed that the eccentric 14 is rotating so asto decrease the distance between its contact with the blade 19 and theaxis of the main shaft 5. Then the blade 19 slides by the force of thesprings 20 in the direction of the arrow a shown in FIGS. 1 and 2 toincrease the volume of the blade chamber with the resultant generationof suction pressure therein. As a result, the ball 27 is detached fromthe suction port 26 against the force of the spring 28, allowing thelubricant in the tubing 11 to pass through the tube end 11!) and suctionport 26 and be sucked into the blade chamber 22 through the valvechamber 24 as indicated by the arrow c of FIG. 3. During this time theelastic plate 29 closes the discharge port 30. When the disk member 14further rotates so as to broaden the distance between its contact withthe blade 19 and the axis of the main shaft, then the blade 19 slidesagainst the force of the springs 20 in the direction of the arrow b ofFIGS. 1 and 2 to reduce the volume of the blade chamber 22 with theresultant generation of compressive pressure therein. At this time theball 27 closes the suction port 26 by said compressive pressure as wellas by the force of the springs 20. On the other hand, said compressivepressure causes the elastic plate 29 to be forced open, so that thelubricant in the blade chamber 22 is forced out into the lubricantreservoir 8 indicated by the arrow (1 of FIG. 4 through the valve cavity24 and discharge port 30. The aforementioned cycles of operation arerepreated according to the rotation of the eccentric 14. Thus thelubricant 9 is forcefully circulated through the following route:

Reservoir 8 tube end 11a tube 11 tube end 11b valve cavity 24 bladechamber 22 valve cavity 24 reservoir 8. The lubricant 9 is cooled bybeing conducted through that part of the lubricant tube 11 whichpenetrates the heat exchanger 12.

This permits the circulation and cooling of lubricant withoutparticularly providing a pump for its circulation, thereby enabling arotary compressor to be built of a small number of easily assembledparts in compact form adapted for quantity production and reduced costwith least possibility of failure.

Further, part of the lubricant in the reservoir 8 is supplied to thespiral groove 37 formed in the main shaft 5 through the lubricantpassage 38 disposed therein mainly to lubricate the slide sections ofthe main shaft 5 and upper frame 6 and those of the eccentric l4 androtor 15. Part of the lubricant 9 sucked into the blade chamber 22lubricates the slide sections of the blade 19, upper and lower frames 6and 17, rotor 15 and cyl inder l6 and those of said rotor 15, upper andlower frames 6 and 17 and cylinder 16.

We claim:

1. A rotary compressor comprising:

tightly closed upper and lower casings, said lower casing defining alubricant reservoir containing a lubricant;

a motor provided with a main shaft and firmly mounted in the uppercasing;

a refrigerant compressing unit actuated by an eccentric fixed to themain shaft;

a blade chamber with a blade reciprocating radially therethrough, saidblade dividing the compressing unit into high and low pressure sides;

a refrigerant tubing comprising a suction line for leading gaseousrefrigerant into the refrigerant compressing unit and a discharge linefor delivering the refrigerant;

a lubricant tubing provided with a heat exchanger and having a first endthereof opened to the lubricant in said lubricant reservoir; and

a mechanism for circulating the lubricant, said lubricant circulatingmechanism comprising a valve unit including a valve chamber whichcommunicates with said blade chamber, and suction port means connectingthe other end of the lubricant tubing with said valve chamber said valveunit selectively causing lubricant to be introduced from said other endof the lubricant tubing to said valve chamber and to said blade chamber.

2. The rotary compressor according to claim 1 wherein said motor is anelectric motor.

3. The rotary compressor according to claim 1 wherein said valve unitincludes: a first check valve between the blade chamber and the otherend of the lubricant tubing for conducting the lubricant from saidtubing to said chamber, and a second check valve between the bladechamber and the lubricant reservoir for discharging the lubricant fromthe chamber to the reservoir.

4. The rotary compressor according to claim 1 wherein said suction portconnects the valve cavity with said other end of the lubricant tubingfor introducing the lubricant to the lubricant tubing into said bladechamber through the valve cavity while said blade is advancing outwardlyof said blade chamber; and

a discharge port connects the valve cavity with the lubricant reservoirfor conducting the lubricant in the blade chamber into said reservoirwhile the blade is receding inwardly of said blade chamber.

5. The rotary compressor according to claim 4 wherein said lubricantcirculating mechanism further comprises:

a ball in the valve cavity for closing the suction port except whilesaid blade is advancing;

a spring in the valve cavity for urging the ball toward the suctionport; and

an elastic plate for closing the discharge port except while said bladeis receding.

6. The rotary compressor according to claim 5 wherein said elastic plateis mounted exterior of said valve unit.

7. A rotary compressor including:

a. tightly closed upper and lower casings, said lower casing defining alubricant reservoir containing lubricant;

b. a motor provided with a main shaft and firmly received in the uppercasing;

c. a refrigerant compressing unit comprising a cylinder disposed belowthe motor, an eccentric fixed to the main shaft in the cylinder, a rotorhaving the eccentric fitted therein and contacting the cylindrical innersurface at that portion of the outer periphery of the eccentric which isremotest from the main shaft;

d. a lubricant tubing having one end connected to the lower casing so asto communicate with the lubricant reservoir;

e. a heat exchanger for cooling the lubricant in the tubing, throughwhich the tubing passes; and

f. a mechanism for circulating the lubricant comprisa blade chamberprovided in the wall of the cylinder,

a blade reciprocating radially of the cylinder through the blade chamberand biased so as to always contact the outer periphery of the rotor, and

a lubricant valve unit provided under the blade chamber, said valve unitcomprising a valve chamber formed therein, a passage formed between thevalve chamber and the blade chamber for mutual communication of thechambers, a suction port provided on the lower casing, said suction porthaving one end connected to the valve chamber and the other end to theother end of the lubricant tubing, a ball disposed in the valve chamberso as to normally close the suction port by a spring in the valvechamber, a discharge port formed between the valve chamber and thelubricant reservoir, and a plate of elastic material mounted on thelower end of the valve unit so as to normally close the discharge port,wherein, when the blade is moved toward the main shaft by the rotationthereof, suction pressure is generated in the blade chamber fordisengagement of the ball from the suction port with the discharge portclosed, thereby causing the lubricant in the valve chamber and thecooled lubricant in the tubing to be introduced into the blade chamberthrough the passage and, when the movement of the blade is reversed byfurther rotation of the main shaft, compressive pressure is generatedinthe blade chamber to make the ball close the suction port and theelastic plate forced open, thereby causing the lubricant in the bladechamber to be forced out in the lubricant reservoir through the passage,valve chamber and discharge port.

8. The rotary compressor according to claim 7 wherein said motor is anelectric motor.

1. A rotary compressor comprising: tightly closed upper and lowercasings, said lower casing defining a lubricant reservoir containing alubricant; a motor provided with a main shaft and firmly mounted in theupper casing; a refrigerant compressing unit actuated by an eccentricfixed to the main shaft; a blade chamber with a blade reciprocatingradially therethrough, said blade dividing the compressing unit intohigh and low pressure sides; a refrigerant tubing comprising a suctionline for leading gaseous refrigerant into the refrigerant compressingunit and a discharge line for delivering the refrigerant; a lubricanttubing provided with a heat exchanger and having a first end thereofopened to the lubricant in said lubricant reservoir; and a mechanism forcirculating the lubricant, said lubricant circulating mechanismcomprising a valve unit including a valve chamber which communicateswith said blade chamber, and suction port means connecting the other endof the lubricant tubing with said valve chamber, said valve unitselectively causing lubricant to be introduced from said other end ofthe lubricant tubing to said valve chamber and to said blade chamber. 2.The rotary compressor according to claim 1 wherein said motor is anelectric motor.
 3. The rotary compressor according to claim 1 whereinsaid valve unit includes: a first check valve between the blade chamberand the other end of the lubricant tubing for conducting the lubricantfrom said tubing to said chamber, and a second check valve between theblade chamber and the lubricant reservoir for discharging the lubricantfrom the chamber to the reservoir.
 4. The rotary compressor according toclaim 1 wherein said suction port connects the valve cavity with saidother end of the lubricant tubing for introducing the lubricant to thelubricant tubing into said blade chamber through the valve cavity whilesaid blade is advancing outwardly of said blade chamber; and a dischargeport connects the valve cavity with the lubricant reservoir forconducting the lubricant in the blade chamber into said reservoir whilethe blade is receding inwardly of said blade chamber.
 5. The rotarycompressor according to claim 4 wherein said lubricant circulatingmechanism further comprises: a ball in the valve cavity for closing thesuction port except while said blade is advancing; a spring in the valvecavity for urging the ball toward the suction port; and an elastic platefor closing the discharge port except while said blade is receding. 6.The rotary compressor according to claim 5 wherein said elastic plate ismounted exterior of said valve unit.
 7. A rotary compressor including:a. tightly closed upper and lower casings, said lower casing defining alubricant reservoir containing lubricant; b. a motor provided with amain shaft and firmly received in the upper casing; c. a refrigerantcompressing unit comprising a cylinder disposed below the motor, aneccentric fixed to the main shaft in the cylinder, a rotor having theeccentric fitted therein and contacting the cylindrical inner surface atthat portion of the outer periphery of the eccentric which is remotestfrom the main shaft; d. a lubricant tubing having one end connected tothe lower casing so as to communicate with the lubricant reservoir; e. aheat exchanger for cooling the lubricant in the tubing, through whichthe tubing passes; and f. a mechanism for circulating the lubricantcomprising a blade chamber provided in the wall of the cylinder, a bladereciprocating radially of the cylinder through the blade chamber andbiased so as to always contact the outer periphery of the rotor, and alubricant valve unit provided under the blade chamber, said valve unitcomprising a valve chamber formed therein, a passage formed between thevalve chamber and the blade chamber for mutual communication of thechambers, a suction port provided on the lower casing, said suction porthaving one end connected to the valve chamber and the other end to theother end of the lubricant tubing, a ball disposed in the valve chamberso as to normally close the suction port by a spring in the valvechamber, a discharge port formed between the valve chamber and thelubricant reservoir, and a plate of elastic material mounted on thelower end of the valve unit so as to normally close the discharge port,wherein, when the blade is moved toward the main shaft by the rotationthereof, suction pressure is generated in the blade chamber fordisengagement of the ball from the suction port with the discharge portclosed, thereby causing the lubricant in the valve chamber and thecooled lubricant in the tubing to be introduced into the blade chamberthrough the passage and, when the movement of the blade is reversed byfurther rotation of the main shaft, compressive pressure is generated inthe blade chamber to make the ball close the suction port and theelastic plate forced open, thereby causing the lubricant in the bladechamber to be forced out in the lubricant reservoir through the passage,valve chamber and discharge port.
 8. The rotary compressor according toclaim 7 wherein said motor is an electric motor.